A cellular network or mobile network can include a wireless network distributed over land areas called cells, each served by at least one fixed-location transceiver known as a cell site or base station. In a cellular network, each cell uses a different set of frequencies or codes from neighboring cells to avoid interference and provide acceptable performance within each cell. When joined together, these cells provide radio coverage over a wide geographic area. This joining of cells enables a large number of portable transceivers (e.g., mobile phones, pagers, etc.) to communicate with each other and with transceivers and telephones anywhere in the network, via base stations, even if some of the transceivers are moving through more than one cell during transmission.
Major telecommunications providers have deployed voice and data cellular networks over most of the inhabited land area of the Earth. This wide deployment allows mobile phones and mobile computing devices to be connected to the public switched telephone network and public Internet. Private cellular networks can be used for research or for large organizations and fleets, such as dispatch for local public safety agencies.